14 CFR 25.207 - Stall warning.

Status message

(a) Stall warning with sufficient margin to prevent inadvertent stalling with the flaps and landing gear in any normal position must be clear and distinctive to the pilot in straight and turning flight.

(b) The warning must be furnished either through the inherent aerodynamic qualities of the airplane or by a device that will give clearly distinguishable indications under expected conditions of flight. However, a visual stall warning device that requires the attention of the crew within the cockpit is not acceptable by itself. If a warning device is used, it must provide a warning in each of the airplane configurations prescribed in paragraph (a) of this section at the speed prescribed in paragraphs (c) and (d) of this section. Except for showing compliance with the stall warning margin prescribed in paragraph (h)(3)(ii) of this section, stall warning for flight in icing conditions must be provided by the same means as stall warning for flight in non-icing conditions.

(c) When the speed is reduced at rates not exceeding one knot per second, stall warning must begin, in each normal configuration, at a speed, VSW, exceeding the speed at which the stall is identified in accordance with § 25.201(d) by not less than five knots or five percent CAS, whichever is greater. Once initiated, stall warning must continue until the angle of attack is reduced to approximately that at which stall warning began.

(d) In addition to the requirement of paragraph (c) of this section, when the speed is reduced at rates not exceeding one knot per second, in straight flight with engines idling and at the center-of-gravity position specified in § 25.103(b)(5), VSW, in each normal configuration, must exceed VSR by not less than three knots or three percent CAS, whichever is greater.

(e) In icing conditions, the stall warning margin in straight and turning flight must be sufficient to allow the pilot to prevent stalling (as defined in § 25.201(d)) when the pilot starts a recovery maneuver not less than three seconds after the onset of stall warning. When demonstrating compliance with this paragraph, the pilot must perform the recovery maneuver in the same way as for the airplane in non-icing conditions. Compliance with this requirement must be demonstrated in flight with the speed reduced at rates not exceeding one knot per second, with—

(1) The more critical of the takeoff ice and final takeoff ice accretions defined in appendix C for each configuration used in the takeoff phase of flight;

(3) The holding ice accretion defined in appendix C for the holding configuration(s);

(4) The approach ice accretion defined in appendix C for the approach configuration(s); and

(5) The landing ice accretion defined in appendix C for the landing and go-around configuration(s).

(f) The stall warning margin must be sufficient in both non-icing and icing conditions to allow the pilot to prevent stalling when the pilot starts a recovery maneuver not less than one second after the onset of stall warning in slow-down turns with at least 1.5 g load factor normal to the flight path and airspeed deceleration rates of at least 2 knots per second. When demonstrating compliance with this paragraph for icing conditions, the pilot must perform the recovery maneuver in the same way as for the airplane in non-icing conditions. Compliance with this requirement must be demonstrated in flight with—

(1) The flaps and landing gear in any normal position;

(2) The airplane trimmed for straight flight at a speed of 1.3 VSR; and

(3) The power or thrust necessary to maintain level flight at 1.3 VSR.

(g) Stall warning must also be provided in each abnormal configuration of the high lift devices that is likely to be used in flight following system failures (including all configurations covered by Airplane Flight Manual procedures).

(h) For flight in icing conditions before the ice protection system has been activated and is performing its intended function, with the ice accretion defined in appendix C, part II(e) of this part, the stall warning margin in straight and turning flight must be sufficient to allow the pilot to prevent stalling without encountering any adverse flight characteristics when:

(1) The speed is reduced at rates not exceeding one knot per second;

(2) The pilot performs the recovery maneuver in the same way as for flight in non-icing conditions; and

(3) The recovery maneuver is started no earlier than:

(i) One second after the onset of stall warning if stall warning is provided by the same means as for flight in non-icing conditions; or

(ii) Three seconds after the onset of stall warning if stall warning is provided by a different means than for flight in non-icing conditions.

(i) In showing compliance with paragraph (h) of this section, if stall warning is provided by a different means in icing conditions than for non-icing conditions, compliance with § 25.203 must be shown using the accretion defined in appendix C, part II(e) of this part. Compliance with this requirement must be shown using the demonstration prescribed by § 25.201, except that the deceleration rates of § 25.201(c)(2) need not be demonstrated.

This action is effective on Bombardier Aerospace on May 27, 2015. We must receive your comments by June 26, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. These design features are electrical and electronic systems that perform critical functions, the loss of which could be catastrophic to the airplane. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

These special conditions are issued for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is a fly-by-wire electronic flight control system that provides an electronic interface between the pilot's flight controls and the flight control surfaces for both normal and failure states. The system generates the actual surface commands that provide for stability augmentation and control about all three airplane axes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on Bombardier Inc. on April 30, 2015. We must receive your comments by June 15, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Bombardier Inc. Model BD-700-2A12 and BD-700-2A13 airplanes. These airplanes will have a novel or unusual design feature associated with an electronic flight-control system that provides roll control of the airplanes through pilot inputs to the flight computers. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on Airbus on April 30, 2015. We must receive your comments by June 15, 2015.

14 CFR Part 25

Summary

These special conditions are issued for Airbus Model A319-151n/171n, A320-251n/271n, and A321-251n/271n (collectively known as Single Aisle new engine option (SA neo)) series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is a new generation of high-bypass engines, and the potential loads resulting from extreme engine-failure conditions. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on April 28, 2015. We must receive your comments by June 12, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Boeing Model 787-9 airplane. This airplane has a novel or unusual design feature associated with side-facing, oblique seats. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for occupants of seats installed at an angle of greater than 18 degrees, but substantially less than 90 degrees, to the centerline of the airplane, nor for airbag devices. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

Effective date: This action is effective on Cessna Aircraft Company on April 6, 2015. We must receive your comments by May 21, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Cessna Model 680A airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is hydrophobic windshield coatings in lieu of windshield wipers. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

These special conditions are issued for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is a nitrogen generation system (NGS) for all fuel tanks that actively reduces flammability exposure within the fuel tanks significantly below that required by the fuel tank flammability regulations. Among other benefits, the NGS significantly reduces the potential for fuel vapor ignition caused by lightning strikes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on Cessna Aircraft Company on March 3, 2015. We must receive your comments by April 17, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Cessna Aircraft Company, Model 650, Citation VII Airplane. This airplane as modified by Universal Avionics Systems Corporation will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is for the installation of Universal Avionics InSight TM Electronic Flight Instrument System (EFIS), Engine Interface Units (EIU), UNS-1Fw Wide Area Augmentation System (WAAS) Flight Management System (FMS), and Terrain Awareness and Warning System (TAWS) Class A, which will use rechargeable lithium batteries and battery systems. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on The Boeing Company on February 26, 2015. We must receive your comments by April 13, 2015.

14 CFR Part 25

Summary

These special conditions are issued for Boeing Model 767-2C series airplanes. These airplanes, as modified by The Boeing Company, will have a novel or unusual design feature associated with airplane electronic-system security protection or isolation from unauthorized internal access. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on The Boeing Company on February 26, 2015. We must receive your comments by April 13, 2015.

14 CFR Part 25

Summary

These special conditions are issued for Boeing Model 767-2C series airplanes. These airplanes, as modified by The Boeing Company, will have a novel or unusual design feature associated with airplane electronic-system security protection or isolation from unauthorized external access. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

The FAA is correcting the final rule, “Harmonization of Airworthiness Standards—Gust and Maneuver Load Requirements” (79 FR 73462), published December 11, 2014. In the rule, the FAA amended certain airworthiness regulations for transport category airplanes to eliminate regulatory differences between the airworthiness standards of the FAA and European Aviation Safety Agency (EASA). It does not add new requirements beyond what manufacturers currently meet for EASA certification and does not affect current industry design practices. This final rule revises the pitch maneuver design loads criteria; revises the gust and turbulence design loads criteria; revises the application of gust loads to engine mounts, high lift devices, and other control surfaces; adds a “round-the-clock” discrete gust criterion and a multi-axis discrete gust criterion for airplanes equipped with wing-mounted engines; revises the engine torque loads criteria; adds an engine failure dynamic load condition; revises the ground gust design loads criteria; revises the criteria used to establish the rough air design speed; and requires the establishment of a rough air Mach number. This document corrects errors in the rule by ensuring that certain letters in the included equations have the right formatting and therefore the correct meaning.

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This action is effective on Bombardier Aerospace on May 27, 2015. We must receive your comments by June 26, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. These design features are electrical and electronic systems that perform critical functions, the loss of which could be catastrophic to the airplane. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

These special conditions are issued for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is a fly-by-wire electronic flight control system that provides an electronic interface between the pilot's flight controls and the flight control surfaces for both normal and failure states. The system generates the actual surface commands that provide for stability augmentation and control about all three airplane axes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on Bombardier Inc. on April 30, 2015. We must receive your comments by June 15, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Bombardier Inc. Model BD-700-2A12 and BD-700-2A13 airplanes. These airplanes will have a novel or unusual design feature associated with an electronic flight-control system that provides roll control of the airplanes through pilot inputs to the flight computers. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on Airbus on April 30, 2015. We must receive your comments by June 15, 2015.

14 CFR Part 25

Summary

These special conditions are issued for Airbus Model A319-151n/171n, A320-251n/271n, and A321-251n/271n (collectively known as Single Aisle new engine option (SA neo)) series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is a new generation of high-bypass engines, and the potential loads resulting from extreme engine-failure conditions. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action proposes special conditions for the Boeing Model 747-8 series airplanes. This airplane, as modified by L-3 Communications Integrated Systems (L-3), will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is therapeutic oxygen for medical use installed in an executive-interior airplane. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on April 28, 2015. We must receive your comments by June 12, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Boeing Model 787-9 airplane. This airplane has a novel or unusual design feature associated with side-facing, oblique seats. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for occupants of seats installed at an angle of greater than 18 degrees, but substantially less than 90 degrees, to the centerline of the airplane, nor for airbag devices. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

Effective date: This action is effective on Cessna Aircraft Company on April 6, 2015. We must receive your comments by May 21, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Cessna Model 680A airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is hydrophobic windshield coatings in lieu of windshield wipers. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

These special conditions are issued for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is a nitrogen generation system (NGS) for all fuel tanks that actively reduces flammability exposure within the fuel tanks significantly below that required by the fuel tank flammability regulations. Among other benefits, the NGS significantly reduces the potential for fuel vapor ignition caused by lightning strikes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action proposes special conditions for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is a fly-by-wire electronic flight control system that provides an electronic interface between the pilot's flight controls and the flight control surfaces for both normal and failure states. The system generates the actual surface commands that provide for stability augmentation and control about all three airplane axes. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on Cessna Aircraft Company on March 3, 2015. We must receive your comments by April 17, 2015.

14 CFR Part 25

Summary

These special conditions are issued for the Cessna Aircraft Company, Model 650, Citation VII Airplane. This airplane as modified by Universal Avionics Systems Corporation will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. This design feature is for the installation of Universal Avionics InSight TM Electronic Flight Instrument System (EFIS), Engine Interface Units (EIU), UNS-1Fw Wide Area Augmentation System (WAAS) Flight Management System (FMS), and Terrain Awareness and Warning System (TAWS) Class A, which will use rechargeable lithium batteries and battery systems. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action proposes special conditions for the Bombardier Aerospace Models BD-500-1A10 and BD-500-1A11 Series Airplanes. These airplanes will have a novel or unusual design feature associated with the fly-by-wire electronic flight control system (EFCS) that limits pitch- and roll-attitude functions to prevent the airplane from attaining certain pitch attitudes and roll angles. This system generates the actual surface commands that provide for stability augmentation and flight control for all three-airplane axes (longitudinal, lateral, and directional). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on The Boeing Company on February 26, 2015. We must receive your comments by April 13, 2015.

14 CFR Part 25

Summary

These special conditions are issued for Boeing Model 767-2C series airplanes. These airplanes, as modified by The Boeing Company, will have a novel or unusual design feature associated with airplane electronic-system security protection or isolation from unauthorized internal access. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action is effective on The Boeing Company on February 26, 2015. We must receive your comments by April 13, 2015.

14 CFR Part 25

Summary

These special conditions are issued for Boeing Model 767-2C series airplanes. These airplanes, as modified by The Boeing Company, will have a novel or unusual design feature associated with airplane electronic-system security protection or isolation from unauthorized external access. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

This action proposes special conditions for the Gulfstream Model GVII-G500 (GVII series) airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is associated with side-stick controllers that require limited pilot force because they are operated by one hand only. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. These proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

The FAA is correcting the final rule, “Harmonization of Airworthiness Standards—Gust and Maneuver Load Requirements” (79 FR 73462), published December 11, 2014. In the rule, the FAA amended certain airworthiness regulations for transport category airplanes to eliminate regulatory differences between the airworthiness standards of the FAA and European Aviation Safety Agency (EASA). It does not add new requirements beyond what manufacturers currently meet for EASA certification and does not affect current industry design practices. This final rule revises the pitch maneuver design loads criteria; revises the gust and turbulence design loads criteria; revises the application of gust loads to engine mounts, high lift devices, and other control surfaces; adds a “round-the-clock” discrete gust criterion and a multi-axis discrete gust criterion for airplanes equipped with wing-mounted engines; revises the engine torque loads criteria; adds an engine failure dynamic load condition; revises the ground gust design loads criteria; revises the criteria used to establish the rough air design speed; and requires the establishment of a rough air Mach number. This document corrects errors in the rule by ensuring that certain letters in the included equations have the right formatting and therefore the correct meaning.